SP PROs can work in either situation, or a combination of both.
DC Coupling is where the Renewable Energy charging source is injected directly onto the DC Bus (Battery System). The hardware required to do this is generally a little cheaper. The efficiency when charging the battery will be maximised using DC Coupling as there is only the Solar Controller in series with the charging. If this is a grid tie system the maximum power that can be exported to the grid is equal to the rating of the SP PRO.
AC Coupling is when the Renewable Energy source (mainly Solar) is connected directly to the AC Bus (SP PRO output) through a Selectronic Certified grid tie inverter. Installation will be quicker and cheaper with this method as the solar panels can be wired at up to 600V DC open circuit. Today’s solar panels generally have MC connectors, which make connecting multiple solar panels in series very easy. Efficiency will be maximised when AC Loads are present during sunlight hours as the PV energy will go directly to the load. AC Coupling can also run higher loads during the day as the output from the grid tie inverters and the SP PRO inverter can be added together. The grid tie inverters can be installed up to 100m away from the SP PRO allowing the PV to be placed exactly where you need it and then run efficient AC cabling back to the AC Bus. If this is a grid tie system, the maximum power that can be exported to the grid is twice the rating of the SP PRO, with a maximum number of five Selectronic Certified grid tie Inverters.